1. Field of the Invention
The invention is directed to a process and a device for repairing cylinders in printing machines, in particular form cylinders, by thermal spray coating.
2. Discussion of the Prior Art
A smooth, cylindrical surface of cylinders in printing machines is a prerequisite for high quality in the printed products produced by these machines. The surface of the cylinders can be destroyed mechanically, e.g. by rolling over hard extraneous materials, by chemical corrosion, wear, etc.
Tampon galvanization is recommended for repair of such cylinder surfaces in an article by Betz, Adolf, entitled "Tampon galvanization - a method for repairing cylindrical structural components", Der Polygraph, 1988, No. 9, pages 807 and 810. However, only localized damaged spots can be repaired with such a method.
The invention described in DD 206 905 proposes a method for repairing cylinders in which an epoxy-containing molding compound is applied by trowel to damaged locations on the cylinder. However, it is also only possible to make local repairs with this method.
Repairs can be made to the entire surface, e.g., by means of thermal spraying. But the cylinder must be removed from the printing machine for this purpose, which substantially increases the cost of repair.